1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method. More specifically, the present invention relates to an image processing apparatus and an image processing method which allow display of a natural-looking stereoscopic image when a stereoscopic image composed of images from multiple viewpoints captured at different consecutive timings is displayed in such a manner that the images from the respective viewpoints are displayed at different consecutive timings.
2. Description of the Related Art
In recent years, apparatuses that support compression schemes such as Moving Picture Expert Group (MPEG), in which image information is handled as digital signals and is compressed using an orthogonal transform such as a discrete cosine transform and motion compensation, by utilizing redundancy specific to image information for the purpose of realizing high-efficiency transmission and accumulation of information have been increasingly prevalent for use in both distribution of information from broadcast stations and receipt of information at general consumer homes.
Specifically, for example, encoding apparatuses and decoding apparatuses that are used when image information (bit streams) compressed using an encoding scheme that utilizes an orthogonal transform such as a discrete cosine transform or a Karhunen-Loève transform and motion compensation, such as MPEG or H.26x, is received via a network medium such as satellite broadcasting, cable television (TV), or the Internet or is processed on a storage medium such as an optical disk, a magnetic disk, or a flash memory have been increasingly prevalent.
For example, MPEG-2 (International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 13818-2) is defined as a general-purpose image encoding method, and is a standard that covers both interlaced scanned images (interlaced images) and progressive scanned images (progressive images) as well as standard-definition images and high-definition images, which is now widely used for a wide variety of applications including professional applications and consumer applications. The MPEG-2 compression scheme facilitates the high compression ratio and high quality implementation of images by, for example, assigning a code rate (bit rate) of 4 to 8 Mbps to a standard-definition interlaced scanned image having 720×480 pixels in the lateral and longitudinal directions or a code rate of 18 to 22 Mbps to a high-definition interlaced scanned image having 1920×1088 pixels in the lateral and longitudinal directions.
MPEG-2 mainly provides high-quality encoding suitable for broadcasting, but does not support encoding systems of a lower code rate (bit rate), that is, a higher compression ratio, than that of MPEG-1. With the increase in popularity of mobile terminals, the demand for such encoding systems will increase in the future. To meet the demand, the MPEG-4 encoding was standardized. As to image encoding, the ISO/IEC 14496-2 standard was approved as an international standard in December 1998.
In addition, Advanced Video Coding (AVC) (MPEG-4 part 10, ISO/IEC 14496-10, International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) H.264) is also standardized. The AVC standard is developed by Joint Video Team (JVT) jointly established by ITU-T and ISO/IEC to promote standardization of image encoding.
AVC is, like MPEG-2 or MPEG-4, a hybrid coding scheme including motion compensation coding and discrete cosine transform coding. In general, AVC involves a larger amount of computation for encoding and decoding than existing encoding schemes such as MPEG-2 and MPEG-4, but makes a higher encoding efficiency feasible.
Meanwhile, with the recent advancement of stereoscopic image capture and display technologies capable of stereovision, content of images to be encoded using the encoding schemes described above may include content of stereoscopic images as well as content of two-dimensional images.
Specifically, an extension of AVC to encoding of stereoscopic images is developed, and standardization of Multiview Video Coding (MVC) that enables encoding of multi-viewpoint images captured using a plurality of image capture apparatuses, which form a stereoscopic image, is developed. A method for encoding and decoding multi-viewpoint images is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2008-182669.
In the following, multi-viewpoint images that form a stereoscopic image will be described in the context of a three-dimensional (3D) image (stereo image), which is composed of two-view images having the minimum number of viewpoints, by way of example.
A left-eye image (hereinafter referred to as an “L image”) that is an image observed with the left eye and a right-eye image (hereinafter referred to as an “R image”) that is an image observed with the right eye, which form a 3D image, may be images captured at the same capture timing or images captured at different consecutive capture timings.
Further, a stereoscopic image is displayed using a dedicated image display apparatus. The display method of the image display apparatus may be a method for displaying an L image and an R image, which form a 3D image, at different consecutive timings, or a method for simultaneously displaying the L image and the R image.